Device for cushioning of compression surfaces

ABSTRACT

According to the present invention, improved methods and apparatus are provided for providing cushioning and other ergonomic surfaces on devices requiring the patient or tissue to be compressed, such as radiography machines, fluoroscopy units, mammography units and the like. In particular a radiolucent pad element is provided for releasable attachment to at least one surface of a compression device to be used under x-ray, for example, during mammography. The pad element of the present invention can be disposable or constructed to be reusable and in some cases may be applied directly to the patient&#39;s breast. Furthermore, a cushioned paddle is provided wherein said compression paddle and said cushion can be separately or integrally formed.

BACKGROUND OF THE INVENTION

The present invention relates generally to medical apparatus and methodsand more particularly to devices and methods for cushioning or paddingthe surface of compression plates applied to body parts for purposes ofobtaining x-ray films for example mammography, or other scans ofcompressed tissue.

Currently, in the case of mammography, a patient's breast is placedunder compression by opposing plates attached to a mammography machine.Once under compression an x-ray is taken to determine the presence orabsence of suspect lesions in the breast tissue (e.g. calcifications,tumors). Approximately 25 million screening mammograms are performedyearly, which is estimated to be only a 50% compliance rate amongpotential patients, meaning that number would double if more patientscomplied with the recommended screening regime. One of the more commoncomplaints from mammography patients is discomfort during compression ofthe breast. Most patients can only tolerate up to 10-11 compressionunits. The current legal limit for clinical mammography is 16-18 units.A device which would reduce discomfort could likely improve compliancefor screening.

An important reason for compressing the breast during mammography is toprovide a thinner cross section of tissue for the x-rays to passthrough. When the breast is compressed, it provides optimal imaging ofthe tissue abnormalities with the lowest possible dose of x-rayradiation to the patient. Furthermore, during a mammogram, it isimportant for the x-ray plate to be free from radiopaque material, sothat the diagnostic film, once processed, can give the physician thebest possible picture of the tissue and any abnormalities.

Although patients may tolerate the pain during compression, there is aneed for improved devices and techniques to provide better screeningoutcomes by enabling the use of higher compression force, and byproviding increased patient comfort during mammograms thereby positivelyimpacting patient compliance with mammographic screening and ultimatelyimpacting early detection of cancer and improving patient survival.

Such improved devices must be radiolucent and made of a relativelyhomogeneous material to avoid striations or other variations on theresulting x-ray image, have a low profile to allow for correctpositioning of the breast in the mammography machine, be easily cleanedor disposable for sanitary reasons, and provide structural support andtactile comfort to the patient (both soft to touch and providing a lessharsh or “cold” surface). In addition, such improved devices will permitthe use of higher compression forces to be applied to the breast duringmammograms without the patient reaching her tolerance level fordiscomfort, resulting in a thinner tissue section, better image quality,and reduced x-ray dose to the patient.

It is an objective of the present invention to provide greater patientcomfort thereby increasing screening compliance (e.g. patientwillingness to have-more regular mammograms by reducing discomfort ofthe procedure). Greater patient comfort also reduces the risk of patientmovement (voluntary or involuntary). Motion artifact, caused by. patientmovement or slippage of the tissue, can result in loss of clarity of themammographic image. It is a further objective of the present inventionto allow for the use of an increased compressive force, for example, upto 16-18 compression units or more thereby providing for a thinnercross-section of breast tissue during the mammogram resulting in anenhanced ability to detect abnormalities in the mammographic image.These objectives are met by the design and use of the present invention.

DESCRIPTION OF THE BACKGROUND ART

Various patents have issued illustrating inventions in the field ofmammography and comfort during x-ray imaging. For example, in the fieldof mammography, U.S. Pat. Nos. 3,963,933, 4,691,333, 4,943,986,5,189,686, 5,553,111 and 5,398,272 describe various fixtures useful forbreast compression. Further, patents have issued describing devices forincreasing comfort during general x-ray procedures, such as U.S. Pat.No. 5,226,070 (radiolucent x-ray mat), U.S. Pat. No. 5,081,657 (buckeywarmer for mammography machine), U.S. Pat. No. 5,541,972 (disposablepadding device for use during mammography) and U.S. Pat. No. 5,185,776(padded cover for x-ray cassette).

SUMMARY OF THE INVENTION

According to the present invention, improved methods and apparatus areprovided for cushioning or providing other patient comfort surfaces ondevices used for compressing the patient's tissue, such as radiographymachines, fluoroscopy units, mammography units and the like. Inparticular a pad element is provided for releasable attachment to atleast one surface of a compression device to be used under x-ray, orother imaging modality.

In a preferred embodiment of the present invention a pad assembly isprovided consisting of a pad element, an adhesive layer and a releasepaper layer allowing for temporary attachment to the applied surface(either the mammography paddle, x-ray plate or directly to the patient'sskin).

An alternative embodiment of the present invention includes a reusablecushioned paddle configured of a self-skinned foam to allow for easycleaning between patients. This embodiment may be replaceable after manyuses or formed integrally wherein the padded surface and the compressionpaddle are assembled as one unit.

The present invention may also incorporate a dispensing unit for accessto single pads for single use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a typical mammography unit having a base and apivoting x-ray unit attached thereto, the x-ray unit including acompression paddle and an x-ray plate.

FIGS. 2A-2B illustrate detailed construction of the x-ray plate and thecompression paddle respectively.

FIGS. 3A-3C illustrate various configurations of compression paddlesutilized during mammography in a standard mammography machine; the shapeand size depending both on the patient's anatomy and the type of x-rayview desired by the physician.

FIGS. 4A-4B illustrate various attachments that can be placed on thex-ray plate to enhance the image, including devices for spot compression-and magnification.

FIG. 5 illustrates a compression paddle and x-ray plate configured foruse in a stereotactic biopsy procedure.

FIGS. 6A-6B illustrate the pad of the present invention having a paddinglayer, an adhesive layer and a release paper layer.

FIG. 7 illustrates the installation of the pad of the present inventionon an x-ray plate.

FIG. 8 illustrates the installation of the pad of the present inventionon a compression paddle.

FIG. 9 illustrates various pad configurations and geometries accordingto the present invention depending on the type of compression paddle orx-ray unit used in a given procedure.

FIG. 10A illustrates an alternative embodiment of the present invention,showing the use of a self-skinned foam fastened to a compression paddleintended for use on multiple patients.

FIGS. 10B-10C further illustrate an alternative embodiment of thepresent invention wherein the pad of and compression paddle are integralas one unit.

FIG. 11 illustrates a further feature of the present invention, namely adispensing unit for storing and dispensing the disposable pads of thepresent invention to promote ease of use and efficiency.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A typical or standard mammography unit used to image the breast whileunder compression is shown in FIG. 1. This unit 10, includes a base 12and a rotating x-ray source 11, comprising an x-ray source 13, a movablecompression paddle 14 and an x-ray plate 15 that holds the film cassette(not shown) as well as serving as a compression surface against whichthe compression paddle-14 can compress tissue e.g. a breast to beimaged. As depicted in FIG. 2A, typically the x-ray plate 15, in certainconfigurations known as a “bucky”, is stationary and includes an opening16 into which an x-ray cassette 17 is placed prior to imaging. The x-rayplate has two patient contact surfaces, a front face 18, and afunctional surface 19. The x-ray plate 15, may optionally includeradiopaque markers 19A at the perimeter of the functional surface 19 toallow various marking schemes to be utilized during a procedure.

FIG. 2B illustrates a more detailed configuration of compression paddle14, including a front patient contact surface 20 and a functionalpatient contact surface 21. Paddle 14 is typically constructed of aclear radiolucent plastic material and is designed to be removablyattached by an interchange assembly 22, to the movable working arm ofthe mammography machine (not shown). These paddles are configured invarious geometries as depicted in FIGS. 3A-3C to accommodate variouspatient anatomies and specific needs of mammographers, such as conedcompression paddles (3A), spot compression paddles (3B) and the axillarypaddle shown as FIG. 3C, all configured to attach to the mammographyunit through standard interchange assembly 22, as shown earlier.

Similarly, the x-ray cassette holder may be adapted by various ancillarymodules such as the spot compression fitting 41 shown in FIG. 4A, and amagnification fitting 42 shown in FIG. 4B. The entire compression system(compression paddle and x-ray plate) can further be modified toaccommodate a stereotactic biopsy procedure as illustrated in FIG. 5. Inthis configuration, compression paddle 14, is modified to include awindow 51, allowing the clinician access to the breast, while stillunder compression, for purposes of placing a device to identify aspecific location in the breast, or to perform an biopsy of tissue.

A preferred embodiment of a pad assembly constructed in accordance withthe present invention is illustrated in FIG. 6A. The pad assembly 60comprises a padding element 61, an adhesive layer 62, and a releasepaper 63 to be removed from contact with the adhesive layer just priorto installation on the surface to be padded. Pad element 61 may beconstructed of various materials having the following characteristics:produce no significant visual artifact on the mammogram (i.e. isradiolucent), be deformable under the forces applied during compressionto provide comfort. Furthermore, the material should provide conformanceto the tissue and the compression surface so as to reduce the propensityfor the material to create air pockets or folds that may be ofsufficient size to be visible on the x-ray image. Additionally, it maybe desirable for the material to be absorptive to external fluids suchas sweat.

Such materials may be an elastomer or gel, open or closed cell foamconsisting of polyolefin, or, preferably a hydrophilic polyurethane opencell foam because of its radiolucent characteristics and soft tactilefeel. The padding material 61 may be a thickness of 0.050″ to 0.500″,preferably in the range of 0.200″ and 0.250″. If an adhesive layer isused, Adhesive layer 62 may be one of a variety of currently availablepressure sensitive adhesives such as acrylic or synthetic rubber basedadhesives, to allow sufficient tackiness for secure attachment to thecompression surface, while also allowing for easy removal (e.g. leavingno detectable residue of adhesive on the applied surface) and disposal.Alternatively, a non-adhesive gel may be used to secure the pad oranother layer of material having a greater coefficient of frictionagainst the applied surface. It is also anticipated by the scope of thepresent invention, that the pad element may itself be textured such thatit is sufficiently “tacky” to enable its use without an adhesive layer,i.e., by means of friction between the element and the tissue and theunit compression surface.

The pad element of FIG. 6A can be configured with adhesive on the entiresurface of the pad, or at certain regions such as just along the border(see FIG. 6C). FIG. 6B depicts a “peel away” packet configuration tohouse the pad assembly. Optionally, the peel away packet can serve as astiffening element to aid installation of the pad by keeping it in aplanar configuration to minimize the possibility of misapplying the pad(leading to inadvertent air pockets or folds in the material, etc.) andto aid in positioning the pad prior to adhering it to the appliedsurface.

FIG. 7 illustrates, in stepwise fashion, the installation of the padassembly 60 of the present invention onto the film holder 15. The firststep comprises opening the packing material housing the pad assembly 60(S1), and thereafter removing any release paper 63 therefrom (S2).Installation on the patient contact surfaces of the x-ray plate 15 areshown in steps S3 and S4, S3 showing the placement of the pad element 61on functional surface 19, and optionally extending to front face surface18. Finally, the pad element may be removed and disposed of and thesequence repeated for the next patient. It may be desirable to score orotherwise provide a fold in the pad element at a fixed point from theedge of the pad to accommodate folding the pad onto the front face ofthe applied surface.

A similar sequence of steps (S1 to S4) is illustrated in FIG. 8 showingthe installation of pad assembly 60 of the present invention ontocompression paddle 14. It should be noted that the pad of the presentinvention may be installed on the x-ray plate 15 and the compressionpaddle 14, or one and not the other, and further optionally on the frontface of either surface depending on the amount of additional cushioningdesired. In experimentation with the present invention, increasedcomfort was noted in all of the various configurations as compared tounpadded compression surfaces.

An alternative technique for use of the pad is to attach it to thebreast of the patient instead of on the mammography machine itself. Inthis technique (not shown) the release paper is removed and the adhesiveside of the pad is-placed directly on the breast in an area of tissue tobe compressed prior to placing the breast into the mammography machine.

Typical geometries of the present invention are illustrated in FIG. 9,including pad elements for x-ray plate 15 (G1), pad elements withwindows for stereotactic use (G2), spot compression paddles (G3), conedcompression paddles (G4), and axillary paddles (G5).

It is noted that while these configurations reflect the geometries ofvarious commercially available compression paddles and x-ray cassetteholders, the present invention may be manufactured in a wide array ofsizes and shapes. The present invention includes pad assemblies, wherethe pad elements are modular (e.g. using more than one pad to cover adesired surface), or cut to fit the desired surface (oversized with anoverlay pattern to guide the operator in cutting the pad to fit).

An alternative embodiment of the present invention is illustrated inFIGS. 10A-10C. FIG. 10A shows a modular configuration of the presentinvention wherein the pad assembly is constructed from a self skinnedfoam (PA), i.e., foam having an impermeable membrane covering, such as avinyl, deployed over a frame (not shown) and fastened to a compressionpaddle by suction cups, magnets rivets or adhesive (AD) on thenon-functional surface of the compression paddle or x-ray plate. Theself-skinned configuration of the pad assembly allows for washing ordisinfecting and can therefore be applied for multiple patients. FIG.10B illustrates a pad assembly (PA) attached to the paddle on thenon-functional surface by snaps or rivets 110.

FIG. 10C further illustrates an alternative embodiment of the presentinvention wherein the pad 120 of and compression paddle 121 are a singleintegral unit.

FIG. 11 illustrates a dispensing unit according to the present inventionfor housing and dispensing the inventive pad assemblies. Dispensing unit100 includes a housing 101 allowing multiple pad assemblies 103 to bestacked for compact storage, and an access slot 102 for allowing theuser to access one pad assembly at a time.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, and equivalentsmay be used. Therefore, the above description should not be taken aslimiting the scope of the present invention.

1-21. (canceled)
 22. A compression device for a mammography unit,comprising: a compression plate having a patient contact surface in anx-ray field of the mammography unit; and a radiolucent pad on thepatient contact surface comprising an impermeable exposed surface forcontacting tissue disposed on the pad within the x-ray field.
 23. Thecompression device of claim 22, wherein the impermeable exposed surfacecomprises an impermeable membrane covering the pad.
 24. The compressiondevice of claim 23, wherein the impermeable membrane comprises vinyl.25. The compression device of claim 22, wherein the pad comprises foambeneath the impermeable surface.
 26. The compression device of claim 22,wherein the pad is removably attached to the compression plate.
 27. Thecompression device of claim 22, wherein the compression plate comprisesa front surface, and wherein the pad is also on the front surface.
 28. Adevice for cushioning a compression surface of a mammography unit,comprising: a radiolucent foam pad comprising first and second surfaces;and an impermeable membrane on the first surface to facilitate cleaningthe first surface.
 29. The device of claim 28, further comprising meansfor releasably attaching the second surface of the foam pad to acompression surface of a mammography unit.
 30. The device of claim 29,wherein the means for releasably attaching is selected from the groupconsisting of suction cups, magnets, rivets, and adhesive.
 31. Thedevice of claim 28, further comprising an adhesive layer on the secondsurface for releasably attaching the pad to the compression surface. 32.The device of claim 31, further comprising release paper removable fromthe adhesive layer before attaching the pad to the compression surface.33. The device of claim 28, wherein the pad is fully skinned.
 34. Amethod for performing mammography using a mammography unit including acompression plate, comprising: placing a spot compression fitting on thecompression plate, the spot compression fitting comprising a patientcontact surface in an x-ray field of the mammography unit, the spotcompression fitting comprising a radiolucent cushioning element on thepatient contact surface; compressing a breast using the spot compressionfitting, the cushioning element deforming under forces applied duringcompression to provide comfort; and obtaining a mammogram of thecompressed breast.
 35. The method of claim 34, wherein the cushioningelement is removably installed on the patient contact surface of thespot compression fitting.
 36. The method of claim 35, further comprisingremoving the cushioning element from the patient contact surface afterobtaining the mammogram.
 37. A method for performing mammography using amammography unit including a compression plate, comprising: placing amagnification fitting on the compression plate, the magnificationfitting comprising a patient contact surface in an x-ray field of themammography unit, the magnification fitting comprising a radiolucentcushioning element on the patient contact surface; compressing a breastusing the magnification, the cushioning element deforming under forcesapplied during compression to provide comfort; and obtaining a mammogramof the compressed breast.
 38. The method of claim 37, wherein thecushioning element is removably installed on the patient contact surfaceof the magnification fitting.
 39. A mammography unit cassette holdercomprising: an imaging area, a first side surface comprising a firsttunnel opening adapted to permit a mammography unit cassette to passtherethrough, a second side surface opposite the first side surface, andan outer side surface; and a compressible x-ray transparent material onat least the imaging area.
 40. The mammography unit cassette holder ofclaim 39, wherein the compressible x-ray transparent material is also onthe outer side surface.
 41. The mammography unit cassette holder ofclaim 39, wherein the compressible x-ray transparent material isremovably installed on the patient contact surface.
 42. The mammographyunit cassette holder of claim 39, wherein the compressible x-raytransparent material is integral with the patient contact surface. 43.The mammography unit cassette holder of claim 39, wherein thecompressible x-ray transparent material comprises a pad and animpermeable membrane covering the pad.
 44. A compression device for aradiography, fluoroscopy, or mammography unit, comprising: a compressionplate having a compression surface in an x-ray field of the radiography,fluoroscopy, or mammography unit; and a radiolucent cushioning elementon the compression surface, the cushioning element producing nosignificant visual artifact on an x-ray while in use.
 45. Thecompression device of claim 44, wherein the cushioning element isremovably installed on the compression surface of the compression plate.46. The compression device of claim 45, further comprising an adhesivelayer on the cushioning element for releasably attaching the cushioningelement to the compression surface.
 47. The compression device of claim44, wherein the cushioning element comprises a foam pad.
 48. Thecompression device of claim 44, wherein the compression plate comprisesa compression paddle.
 49. The compression device of claim 44, whereinthe compression plate comprises a bucky.
 50. A method for performingmammography using a mammography unit including a compression plate,comprising: providing a radiolucent cushioning element on thecompression plate in an x-ray field of the mammography unit; compressinga breast using the compression plate, the cushioning element deformingunder forces applied during compression to provide comfort; andobtaining a mammogram of the compressed breast, the cushioning elementproducing no significant visual artifact on the mammogram.
 51. Themethod of claim 50, wherein the cushioning element comprises a foam pad.52. The device of claim 28, wherein the means for releasably attachingthe pad to a radiography, fluoroscopy, or mammography unit comprises ahook and loop fastener.
 53. The device of claim 52, wherein the meansfor releasably attaching the pad to a radiography, fluoroscopy, ormammography unit is attachable to another surface than the patientcontact surface.
 54. A mammography unit comprising: a mammography unitcassette holder which comprises an imaging area; a first side surfacesubstantially perpendicular to said imaging area comprising a firsttunnel opening adapted to permit a mammography unit cassette to passtherethrough; a second side surface opposite said first side surfacecomprising a second tunnel opening adapted to permit a mammography unitto pass therethrough; and an outer side surface substantiallyperpendicular to said imaging area, said first side surface, and saidsecond side surface; wherein said imaging area comprises a firstcompressible material wherein said material is x-ray transparent; and anx-ray source, a compression device, and a support member to which saidmammography unit cassette holder is attached.